[Insight-users] DeformableRegistration6 error

[Luis Ibanez]

Hi Kingaza,

This is a known problem of the LBGSOptimizer that tends to happen
when  at the first iteration the optimizer doesn't find a better point
to move in the parametric space.

It is unrelated to the fact that you are reading DICOM files and it is
unrelated to the image size.  The real cause is that you are inadvertedly
starting the optimizer in a local optimium.


Please try the new example

                    DeformableRegistration7.cxx

That uses the modified optimizer

                            LBFGSBOptimizer


This example was committed recently in CVS, so you will
have to update your CVS checkout in order to get the file.

http://www.itk.org/cgi-bin/viewcvs.cgi/Examples/Registration/DeformableRegistration7.cxx?rev=1.1&root=Insight&sortby=date&view=log


   Regards,


        Luis


------------------------------------
kingaza at gmail.com wrote:

>hi all,
>
>I try DeformableRegistration6 using images which size is 256*256, but
>an exception occures:
>
>itk::ExceptionObject (0108F840)
>Location: "Unknown"
>File: .\itkLBFGSOptimizer.cxx
>LIne: 252
>Description: itk::ERROR: LBFGSOpimeizer(00376680): Error occured in optimization
>
>and then i debug deeply, and find in itkLBFGSOptimizer.cxx
>parameters.size = 0 while initialPosition.size() =128
>this is where the exception is caught.
>I had thought it is because of the dicom file format , so I try it
>again using png file, and the same appears.
>But if I use images which size is 64*64, anything is OK, and the
>output is perfect.
>please help me!
>
>
>
>itkLBFGSOptimizer.cxx
>/////////////////////////////////////////////////////////////////////////////////////////////
>......
>  m_VnlOptimizer->minimize( parameters );
>
> if ( parameters.size() != initialPosition.size() )
>    {
>    // set current position to initial position and throw an exception
>    this->SetCurrentPosition( initialPosition );
>    itkExceptionMacro( << "Error occured in optimization" );
>    }
>......
>/////////////////////////////////////////////////////////////////////////////////////////////
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